I decided to integrate DAX Formatter into the forum. You will note a new button above the edit box when you type a post called DAX. Use this to wrap your DAX code and then press "Preview" to validate the dax is correct. If it is not correct, you will have to work out what is wrong yourself, or go to DAX formatter for help. So there are times when this will be useful and times when it wont be useful (eg if you don't know how to write the DAX).

So I use it when it makes sense, and use the CODE tags when the DAX tags don't make sense.